Table of Contents

1. Overview of GPIB

For more than 40 years the IEEE 488 bus, also known as the general-purpose interface bus (GPIB), has provided a standard, high-speed interface for communication between instruments and controllers from a multitude of vendors. GPIB is used across a wide variety of industrial instrument control applications.

2. Assembling GPIB Instrument Control System

Setting up the PC. PCI-based GPIB controller boards offer a simple, seamless bridge between the PC and the GPIB instrument. Additionally, stand-alone GPIB controllers communicate via serial, USB, or Ethernet/LXI. As a result GPIB instruments can transmit their data across the room or around the world. Additionally, the National Instruments Instrument Driver Network has more than 7,000 instrument drivers to choose from, as well as tutorials on how to use them to control your instrument.

Configuring the Controller. Depending on the GPIB controller manufacturer, some kind of instrument control software driver will need to be installed before the device will function. National Instruments GPIB controllers come with their own GPIB driver (NI-488.2) and Measurement & Automation Explorer (MAX). MAX scans for connected instruments, confirms communication, and creates the necessary handles for programming.

Connecting GPIB Controller to Instrument. Once the controller is installed and working properly, the GPIB cable can be connected from the controller to the instrument. In accordance with the IEEE 488.2 standard, with a single controller you can control up to 15 different instruments connected in either a daisy-chain or star topology.

If you are using a National Instruments controller, the MAX utility comes with the NI-488.2 driver for your controller. MAX makes GPIB instrument detection and control easy by providing you tools to search for connecting instruments, and send and receive communication with your device.

Open MAX by going to Start>>Programs>>National Instruments>>Measurement & Automation.

Figure 1. MAX Main Menu

To confirm that your GPIB device is connected properly, expand the Devices and Interfaces subdirectory below My System. Then, select your GPIB controller. In this tutorial we are using a USB-GPIB controller. If you are using a PCI, serial, or Ethernet controller, the name may be slightly different. Click on Scan For Instruments.

Figure 2. Scanning for Instruments in MAX

If your GPIB device is SCPI compliant, the name and address will appear in main window.

MAX takes care of creating the necessary resources for VISA communication with your GPIB instrument. By selecting the instrument in from the subdirectory on the left, and then selecting its VISA Properties tab (circled in red at the bottom of Figure 4), you can change the VISA Alias of the device and communicate with it by clicking on “Communicate with Instrument” (SCPI commands), or Open VISA Test Panel (VISA commands).